1. Field of the Invention
The present invention relates to a technique for supporting driving at an intersection and especially relates to a technique which attracts drivers' attention by an alarm when a vehicle intends to proceed into the intersection and cross the opposite lane.
2. Description of the Related Art
Patent document 1 discloses a service to provide information for notifying a vehicle waiting for turning right that an oncoming vehicle is driving straight through and approaching. Patent document 1 discloses that this service is used for right-turn start determination when an oncoming vehicle cannot be seen from a driver, or when the oncoming vehicle is hard to be seen from the driver. In this service, because it is not necessary to provide the information when the driver can certainly confirm that an oncoming vehicle is not approaching and can turn right without slowing down or stopping temporarily, the information is provided when an own vehicle travels at a constant speed or less.
[patent document 1] JP 2009-32067A
In a driving support control in the case of turning right on a road kept left, drivers' attention is attracted by an alarm such as screen display and sound output by using detection information by an object detection sensor in a roadside machine and oncoming vehicle information by vehicle-to-vehicle communication to support the prevention of collision with an object such as an oncoming vehicle and a pedestrian. However, if an alarm is output even in the case of no or low risk of collision, the alarm might annoy a driver and disturb safe driving.